<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      background-color: #ccc;
    }

    #app {
      width: 400px;
      margin: 20px auto;
      background-color: #fff;
      border: 4px solid blueviolet;
      border-radius: 1em;
      box-shadow: 3px 3px 3px rgba(0, 0, 0, 0.5);
      padding: 1em 2em 2em;
    }

    #app h3 {
      text-align: center;
    }

    .title {
      display: flex;
      justify-content: space-between;
      align-items: center;
      border: 1px solid #ccc;
      padding: 0 1em;
    }

    .title h4 {
      line-height: 2;
      margin: 0;
    }

    .container {
      border: 1px solid #ccc;
      padding: 0 1em;
    }

    .btn {
      /* 鼠标改成手的形状 */
      cursor: pointer;
      display: block;
    }
  </style>
</head>

<body>
  <div id="app">
    <h3>案例：折叠面板</h3>
    <div>
      <div class="title">
        <h4>芙蓉楼送辛渐</h4>
        <span class="btn" @click="collapse">
          收起
        </span>
      </div>
      <div class="container">
        <p v-show="isshow">寒雨连江夜入吴,</p>
        <p v-show="isshow">平明送客楚山孤。</p>
        <p v-show="isshow">洛阳亲友如相问，</p>
        <p v-show="isshow">一片冰心在玉壶。</p>
      </div>
    </div>
  </div>
  <script src="../../v2_base_classes/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data:{
        isshow:true
      },
      methods:{
        collapse(){
          this.isshow=!this.isshow
        }
      }
    })
  </script>

</body>

</html>